Monday as first day of week in GNOME

A lot of approaches on the Net specify hacking the locale files; e.g.:
  http://ubuntuforums.org/showthread.php?t=813945

However, a far simpler and certainly less intrusive procedure is to simply modify default LC_TIME:
  http://askubuntu.com/questions/6016/how-to-set-monday-as-the-first-day-of-the-week-in-gnome-calendar-applet

Specifically:

• in /etc/default/locale add:
  LC_TIME="en_GB.UTF-8"
• log out, then log back in